Gates’ close friend Warren Buffett, who once owned a license plate that read “THRIFTY," is another billionaire who refrains from spending serious money on clothing. “I’m happy in a pair of khakis and a sweater,” the Berkshire Hathaway CEO told CBS News in 2013. “I don’t need fancy clothes.”

Other well-heeled individuals prefer using repetition to limit their spending. Michael Bloomberg, worth an estimated $55 billion, reportedly wore the same two pairs of black loafers for more than 10 years. “You do something called resoling and re-heeling," the former New York City Mayor and businessman told the New York Post in 2010. "You don't have to throw them away and get new ones, you can just use the old ones.”

Former U.S. president Barack Obama is also a fan of repeating outfits. In a 2017 interview with Vanity Fair, Michelle Obama revealed that her husband wore the same tux and shoes for eight years straight. “And he was proud of it, too," said the former First Lady.

And it’s not just men who take an economical approach to shopping for clothes. Thrive Global founder Arianna Huffington told CNBC Make It that she’s a big believer in donning the same clothing over and over.

“Women waste so much money and so much attention, and stress out so much believing they have to always wear a new outfit for every occasion," she explained. “I love finding outfits I like and repeating them again and again and again."

Then there’s Oprah Winfrey, who recently became one of the 500 richest people in the world with a net worth of $4.02 billion. The media mogul opened up about her penny-pinching habits on the OWN network, and said that she saves pantyhose with runs in them so they can be repurposed into DIY Spanx.

As for Gates, he does enjoy some luxuries, like frequent travel, and he owns a Porsche 911 and a plane. “But beyond that extravagance,” he told the Telegraph in 2010, “how much food can you eat, how many clothes can you wear?”

The tech guru noted in his Reddit AMA that he believes people’s spending habits are set in high school. And while he won’t break the bank when shopping for himself, it’s a different story when it comes to Melinda Gates.

“I do like to buy nice things for my wife,” he admitted.

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